Begin work on a data request API (#4045)

[Core] Data Deletion And Disclosure APIs

 - Adds a Data Deletion API
   - Deletion comes in a few forms based on who is requesting
   - Deletion must be handled by 3rd party
 - Adds a Data Collection Disclosure Command
   - Provides a dynamically generated statement from 3rd party
   extensions
 - Modifies the always available commands to be cog compatible
   - Also prevents them from being unloaded accidentally

redbot/cogs/audio/apis/playlist_wrapper.py

@@ -27,6 +27,7 @@ from ..sql_statements import (
     PRAGMA_SET_read_uncommitted,
     PRAGMA_SET_temp_store,
     PRAGMA_SET_user_version,
+    HANDLE_DISCORD_DATA_DELETION_QUERY,
 )
 from ..utils import PlaylistScope
 from .api_utils import PlaylistFetchResult
@@ -58,6 +59,8 @@ class PlaylistWrapper:
         self.statement.get_all_with_filter = PLAYLIST_FETCH_ALL_WITH_FILTER
         self.statement.get_all_converter = PLAYLIST_FETCH_ALL_CONVERTER
 
+        self.statement.drop_user_playlists = HANDLE_DISCORD_DATA_DELETION_QUERY
+
     async def init(self) -> None:
         """Initialize the Playlist table"""
         with concurrent.futures.ThreadPoolExecutor(max_workers=1) as executor:
@@ -247,3 +250,11 @@ class PlaylistWrapper:
                     "tracks": json.dumps(tracks),
                 },
             )
+
+    async def handle_playlist_user_id_deletion(self, user_id: int):
+        with concurrent.futures.ThreadPoolExecutor(max_workers=1) as executor:
+            executor.submit(
+                self.database.cursor().execute,
+                self.statement.drop_user_playlists,
+                {"user_id": user_id},
+            )